Locking devices have been used in the past to lock a truck or other vehicle to a dock during a loading operation to prevent the truck from accidentally moving away from the dock. Movement of the truck away from the dock, while the loading operation is proceeding, can cause injury to workmen or damage to material handling equipment, or to the cargo being loaded.
In general, locking devices, as used in the past have been amounted on the dock and have been operated either manually or automatically to pivot a locking member or hook into engagement with the underride prevention bumper, commonly referred to as an "ICC" bumper, which is located at the rear of the truck. With a manual type of locking device, the operator, after the truck has backed into position in front of the dock, manually pivots the hook, or locking member, to a locking position in engagement with the truck bumper and locks the hook in this position. After loading is completed, the hook is manually released and returned to its storage position. As the hook is relatively heavy and is located on the front surface of the dock in a rather inaccessible location, it is a difficult task to manually engage and disengage the locking hook. As a consequence, there is no assurance that the operator will utilize the locking device.
Other types of truck locking mechanisms have been proposed which can be actuated by controls on the dock. Locking devices of this type, which can either be hydraulically or electro-mechanically operated, require push-button activation by the operator to move the locking device to the locking position and to disengage the locking device after the loading operation has been completed.